Secretary for the Environment Edward Yau hopes revised proposals on banning idling vehicles with running engines can be legislated and implemented as early as possible.

Speaking on two radio programmes today, Mr Yau said the revisions, such as allowing different exemptions for taxis, minibuses and coaches, are reasonable.

He noted the trade's requests and operational needs have been taken into account, adding public education will be stepped up.

While admitting the current air pollution index is outdated, Mr Yau said a consultancy review is nearly completed and the Government plans to put forward a package of options in 12 months to consult the public on the new benchmark Hong Kong should adopt.

He said people should consider the pace, the measures and the price they are ready to pay, noting the sulphur dioxide emission by local power plants must be cut by 95% if Hong Kong is to meet the World Health Organisation's highest criterion.

To have an earth-shaking change to the power-generation mode in a day is impossible, Mr Yau said, so a pragmatic step-by-step approach should be studied.

He felt encouraged by the National Development & Reform Commission's recent release of the Framework for Development & Reform Planning for the Pearl River Delta Region.

The framework suggested more co-operation on environmental protection between Hong Kong and the PRD region, and the forming of a regional quality green living area.